Demagnetizer.



PATENTED MAY'ZB, 1907. D. M. BLISS.

DEMAGNETIZER.

APPLIOATION FILED MAR. 1, 1906.

Taga? To all whom it may concern:

UNITED STATES- DoNALD M, BLIss, oIALTY PATENT OFFICE.

or NEW YORK, N. Y., AssIGNoR To ENGINEERING sPE- ooMPANY, A CORPORATION oF NEW YORK,

Be it known that I, DoNALD M. BLIss, a

i subject/of the King of Great Britain, residi valternatel purpose o the present invention is to provide in New York, county of. New York, an State of New York, have invented an'Imrovement in Demagnetizers, of which the lollowing description, in connection with the -accompanying drawings, is a specificatiOn, likeletters on the drawings representing like parts.

The present invention relates to a demagnetizer, and is embodied'in an electrical instrument for demagnetizing small articles, being especially adapted for jewelers* use for demagnetizirig watches. v

The demagnetization is accomplished by placing the article to be demagnetized in a magnetic field produced by currents'fiowing in opposite directions, and the the device with means for automatically producing such a `magnetic field, it being practic'able, moreover, in connection with the invention, to vary the strength of the current which produces the magnetic field during the operation of the device.` For thispurpose the device embodying the invention is provided-with a solenoid of suflii directions,

cient size to admit the insertion of the article to be demagnetized, the said solenoid having two Windings to convey current in opposite combined with means for alternately connecting said windings in circuit with a suitable source of current.V The means for changin the connections are automatic,'as will be the device may ber set in operation by means of a simple switchr push button to close an electric circuit. through the device, an additional feature of the invention, however, being embodied' the combination with the elements named, of a rheostat, so that the current used for demagnetizing is not only alternated in direction, but varied in strength.

Figure 1 is a pers i ective view of an instrument embodying t e invention; and Fig. 2 is a diagram showing the circuit connections.

Referring to Fig. 1,` thesolenoid is contained in a casing A which is mounted-u on a frame or support B, the said solenoid eing so shaped as to afford an opening A2 for the insertion of the article to be demagnetized, such, for exam le, asia watch. As indicated in Fig..2, t e solenoid is provided with Specfication of/Letters Patent.

Application fiIed March 1,1906'. Serial No. 303,621.

ereinafter described, andtherefore,

Patented May as, eov.

,minal T of a Vcircuit from a suitable source of current, herein indicated as a lamp socket L. The opposite ends of the coils a, a2 are arranged to be alternately connected with the otherterminal T2 of the source of current. In order that the coils may be consecutvely ener'gized-so as ,to reverse the flow of current through the solenoid, electro-magnets b, b2 are employed, and an armature c is arranged to coperat with'said electro magnets, and to constitute a circuit controller. The coil a is herein shown as connected through a conductor 3 with one terminal of the electromagnet b,-the opposite terminal of which is connected, through a conductor 7, with a contact member 'd which is arranged to be connected ythrough the armature c anda oonductor 4 with the terminal T2 of the source of current. The armature c, however, is provided IWith a light spring e2 which maintains the'said armature normally in contact with a contact member e to which current is conveyed through the conductor 5, electro-magnet 62 and conductor-6.l

In the simplest formof the instrument, the main' circuit from the terminal T to the terminal T2 is closed by means of a push button f, the consequence being that 'current will flow from the terminal T through the conductor 2, coil az, conductor 5, electro magnet b2, conductor 6, contact member e, armature c and conductor 4 to the terminal T2. This will energi'ze the electro magnet b2, attracting the armature c and closing a circuit through the coil a which may be traced as before, from the terminal T, through conductor 2, coil a, conductor 3, electro-magnet b, conductor 7 contact-member d, armature c, and conductor 4, to the terminal Ti This energizes the electro-magnet b and causes the armature to be attracted thereby, and restored to its original position, it being obvious, that so long as current is flowing through the instrument, the armature c will vibrate, causing in opposite directions through the solenoid A.

In the simple form of the Instrument above described, the effective strength of the current acting on the article to be dema netized may be varied by slowly changingt e position of the article, (a watch, for example) current to flow alternately' with relation to the solenoid, that is to say,"

by gradually inserting the watch and graduvFor thisipurpose, the instrument may be prov yided with a rheostat G, herein shown as pro- 4 vided with three resistance coils g at opposite sides of the main connection through the conductor 8 with'the terminal T, a rotating or oscillating switch arm 92 adapted .to travel consecutively over contacts gsbeing shown as provided at the outside of the casing with a crank handle g4. The switch army2 is connected with' the conductor 2, so that the circuits heretofore traced may be controlled by operating the rheostat, it being obvious, however, that,iin movin the rheostat arm the entire length provide for byl the stops q5 '(Fig. l) the current will be gradually inf creased, and then gradually decreased.

It is obvious that the stops g5 may be omitted and the crank handle 94 revolved, if desired, the oscillating movement provided for, however, being-fully as convenient. .I

From the foregoing description it will be seen that the instrument is substantially automatic, it being practicable to regulate the. speed of variation in the direction of the current in accordance with the inertia of! the armature'c. .This has the advantage over a mechanically operated device that the speed of the alternations is beyond the control of.\ the operator, being dependent upon the primary adjustment of the instrument itself.

It is to be understood that the instrument may be provided With both the push-button f and the rheostat G, as shown, although either one may be employed alone, the advantage above described over the mechanic- I ally operated device being equally true when the'rheostat is employed, for the reason that the different manpulations of the rheostat will only vary the speed of changing the. strength of the current without affectng the time of the alternations in direction. It is to be lfurther noted that the frame or su port B also constitutes an inclosing case for t e electro-magnets, armature, contacts, etc., so that the instrument is neat in appearance, compact, and protected as to the working parts, from dust and moisture. Furthermore, as

' shown in Fig. 1, the solenoid coils are also completely inclosed and protected.

.v esmi/lss What I claim is:

1. In a demagnetizer, a solenoid having two windings in o posite directions; and means for alternate y connecting the said 'windings in circuit from a suitable source of current, whereby the direction of flow of current through theI solenoid is reversed at intervals.

.2. ln a demagnetizer, a solenoid having two reversely wound coils; and an electro- 'magnetic device for alternately connecting said coils-in circuit with a suitable source of current. v

3. A demagnetzer having a solenod provided with cols reversely wound; an electromagnet in circuit` with each coil; and a switch controlled by said electro magnets for electrically' connecting said coils in circuit with a suitable source of current.

4. In a demagnetizer, the Lcombination with a solenoid provided with reversely wound coils; of an electro magnet in circuit with each coil a vibrating armature located in the ma netic field of both electrojnagnets; a circuit c oser for closing said circut through one electro magnet when said armature s attracted by the other; and means for controlling the main circuit through the instrument.l 5. In a demagnetizer, the combination with a solenoid having reversely wound coils; of an electro magnetic switch for alternately connecting said coils in circuit wth a suitable source of current; and a manually operated circuit closer for closing the circut throu h said demagnetizer.

q6. n a demagnetizer, the combination with a solenoid having lreverse windings of a circuit for each Winding; an electro-magnetic device for alternately closing said circuits and a rheostat to control the main circuit through the instrument, whereby the stren th of the current is gradually varied. 7. n a demagnetizer, the L combination with an inclosed solenoid having reverse windings; of a circuit for each winding; an electro-magnetic device for alternately controlling said circuits; and an inclosing case for said electro-magnetic device, said case also constituting a support for the solenoid.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.4

DONALD 'M. BLISS.

IOO 

